Pulp screen flow pipe



Feb. 5, 1952 v s, ANDERSON r 2,584,247

- PUMP SCREEN-FLOW FIFE Filed June 4, 1948 I 4 '1 FIG; 5 26 30 4 FIG. 4

FIG. 7 5o 5o 0 INVENTOR.

EMITT s. ANDERSON ARGHIBALD HALEY FIG. 6

Patented Feb. 5, 1952 T DFFICE PULF SEREEN FLOW PIPE Emitt Anderson and Archie B. Haley, Kenora, Ontario, Canada, assignors to Minnesota and Ontario Paper Company, Minneapolis, Minn.

Application June 4, 1%8, Serial No. 31,165

try, and is more especially concerned with the.

pulp screening machine of the inflow type.

It is the chief object of the invention to im- Prove .flow pip to pu p screenin machines wi h a ew to eliminating or sub tantially eliminatin a oiaams zcl. 92-29) e col ection of slime which normally accum la s n th type oi new inlet heretofore e1nployed r Other and iurther objects of the invention and the advanta es f the same will be pointed out.

her inafter ind cated in the-appended claims, r I

ture, but it is to be understood that it is here presented for illustrative purposes only and is not to be accorded anyinterpretation such as might have the efiect of limiting what is claimed as the invention short of its true and-comprehensive scope in the art.

Referring to the drawings:

Figure 1 is a cross section of the vat and tailing spout and an end view of the drum and cylindrical screen of an inflow rotary screen; I

Figure 2 is a top plan view of the improved flow pipe;

Figure 3 is a sectional view through the flow pipes shown in Figure 2;

Figure 4 is a view of the single flow pipe showing one means of removably securing a closure cap thereon;

Figure 5 is a perspective view of a clip used in connection with securing the removable ends to the flow pipe;

Figure 6 is a side elevational view of the bafiie; and

Figure 7 is a sectional view of the end cap.

There are several makes of what is known as an inflow rotary type screen which differ slightly in mechanical design and in other details. The type disclosed in Figure 1 is used almost entirely in connection with a paper machine where a screen is required to break up fiber bundles and to keep foreign material from reaching the paper machine. In the latter case, the pulp stock is supposed to be properly screened before being sent to the paper machine, and this type of screen shown in Figure l is used. more as an insurance against accidents due tothe presence of some foreign material that may have found its way into the prepared stock during its manipulation in the paper mill.

In Fi ure 1 is a cross sectional view of an inflow rotary screen. The principle under which this machine operates is that of gravity combined with a slight suction. The diiierent parts include vat I 0, cylinder screen i2, polygonal drum M, tailing spout l6, and clean-out port it. The accepted stock flows longitudinally and out one end of the apparatus. l5 indicates generally the stock inlet or flow pipes which consist of pipes 20 and 22. Pipe 20 is provided with a flanged end 24 and is the end which receives the stock from a source not shown. The opposite end of pipe 20 is closed by removable end 010- sure 25 and is held in place by clip 28 secured to the pipe 20 and cooperating with pin 44 and bar 3!) carried by the cap member 26. Pipe 20 is connected by pipes 32 and 34to pipe 22. It is generally preferred that pipes 20 and 22 be of larger diameter than the pipes 32 and 34. By way of example, pipes 20 and 22 may be of 6" y, diameter and the connecting pipes 32 and 34 be of '4" diameter. Pipe 22 is provided with a remov- Qable end 32 which is secured in place similar to cap 26 of pipe 20 and the opposite end of this pipe is provided with a closed end. Pipe 22 is provided with a series of outlets 38 and generally it is preferred that members 40 be secured to the pipe at the outlets as shown in Figure 3. The end closures may be of various construction but it is generally preferred that the closure be similar to that shown in Figure 7. The end closure 26 is provided with a groove 48 to receive a sealing ring such as a rubber washer. The bafiie 36 is in the form shown in Figure 6 and it may be secured in position by welding through small spaced drilled openings along the bottom and at each projection 50 on top.

In operation, the pulp from a suitable source flows through the open end of pipe 20 and through pipes 32 and 34 to outlet pipe 22. Located in outlet pipe 22 is baflie 36 to prevent surges and uneven flow through the outlet 38. The pulp flowing through outlet 38 is at sufiicient flow onto the screen l2 where the tailings are removed from the acceptable stock. By the arrangement shown in Figure 2, the accumulation of slime is substantially eliminated and provides easy means for clean up. The removable ends 26 and 42 are open and the pipes can easily and quickly be cleaned by a high pressure cleaner,

thus reducing'the clean up time over the type of I inlet flows heretofore used.

It is preferred that pipes 20 and 22 are coated with an acid and alkali resistant material such that very little, if any, slime will accumulate in a pipe under pressure, and in producing this invention, the idea is to restrict the flow into the screen through a proper opening on one side so that pressure would be built up in the flow pipe. To obtain uniform distribution, it is necessary to use two pipes with a valve control on the shorter one from the main header, and have two inlets from pipe 20 to pipe 22 with a baflle in the dis tribution pipe 22. The arrangement obtains even distribution and increases the screen capacity. It has been found generally that only one set of fiow pipes are necessary to each screen, and preferably should be located on the up-coming side of the rotating cylinder.

What is claimed as new is:

1. In a rotary pulp screen, means for delivering pulp to the screens under pressure, said means comprising a first conduit for receiving pulp, a second conduit longer than the first conduit and for receiving pulp from the first conduit and delivering the pulp through restricted passages to the pulp screen, spaced conduits of smaller size than the first and second conduits connecting the first and second conduits, a baffle in the second conduit and positioned adjacent the delivery passages and between the delivery passages and discharge end of spaced conduits connecting the first and second conduits, and removable means for closing one end of each or" the first and second conduits,

2. The combination of a vat, a rotatable cylindrical pulp screen mounted in said vat, a pulp delivery means positioned above the vat and over .the pulp screen, said pulp delivery means comprising two conduits of substantially the same diameter but of unequal length, two pipes of a diameter smaller than the diameter of the two conduits connecting the two said conduits, one of said conduits having pulp delivery passages therein, a baflle substantially the length of the second conduit and secured adjacent the delivery passages, each of the said conduits having a removable cover on one end, and the conduits coated at least on the inside with an acid and alkali resisting material.

3. The combination of a vat, a rotatable cylindrical pulp screen mounted therein, a pulp delivery means positioned above the vat and over the pulp screen, said pulp delivery means com prising two conduits positioned in substantially the same horizontal plane and of substantially the same diameter but of unequal length, conduits, means of less diameter connecting the two conduits, a baffle welded to the interior of one of said conduits, said conduit having a baflie welded therein provided with pulp delivery passages located adjacent the baflie, and lip-like members secured to the conduits along the pulp delivery passages.

EMIT'I' S. ANDERSON. ARCHIE B. HALEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 287,164 Reinicke Oct. 23, 1883 424,342 McNamar Mar. 25, 1890 753.730 Owen Mar. 1, 1904 1,054,323 Steele Feb. 25, 1913 1,399,653 Pope Dec. 6, 1921 1,505,835 White Aug-19, 1924 1,532,597 Metcalf Apr. 7, 1925 1,572,498 McClay et a1 Feb. 9, 1926 1,610,742 Bucking Dec. 14, 1926 1,718,399 Anderson et al. June 25, 1929 1,990,992 Lang et al Feb. 12, 1935 2,185,868 Schaefer Jan. 2, 1940 2,351,905 Basler June 20, 1944 2,447,420 Moore Aug. 17, 1948 FOREIGN PATENTS Number Country Date 44,641 Sweden of 1917' 

